A pentasil-type zeolite having a higher BET specific surface area has been investigated since a high activity, a high yield, and a long lifetime of the pentasil-type zeolite as a catalyst as well as high adsorption of the pentasil-type zeolite as an adsorbent or high ion exchange rate of the pentasil-type zeolite as an ion exchanger can be expected. As the pentasil-type zeolite having a higher BET specific surface area, a microcrystalline pentasil-type zeolite and a thin-layered pentasil-type zeolite have been investigated.
As the microcrystalline pentasil-type zeolite, ZSM-5 that is obtained from a starting mixture having a SiO2/Al2O3 molar ratio of 350 and has a BET specific surface area of 412.5 m2/g and an acid amount measured by an ammonia-TPD method of 0.24 mmol/g has been reported (Patent Literature 1). Patent Literature 2 reports a microcrystalline pentasil-type zeolite having a SiO2/Al2O3 molar ratio of 15 and a BET specific surface area of 415 m2/g.
On the other hand, as the thin-layered pentasil-type zeolite, an MFI type zeolite composed of a multilamellar structure that is synthesized using an organic surfactant having two ammonium functional groups and has a SiO2/Al2O3 molar ratio of 96, a BET specific surface area of 520 m2/g, and a solid acid amount measured by an ammonia-TPD method of 0.31 mmol/g has been reported (Non-Patent Literature 1).
Non-Patent Literature 1 also reports an MFI type zeolite composed of a unilamellar structure having a SiO2/Al2O3 molar ratio of 106, a BET specific surface area of 710 m2/g, and a solid acid amount measured by an ammonia-TPD method of 0.33 mmol/g.
A thin-layered pentasil-type zeolite that is obtained from a starting mixture containing tetrabutylphosphonium hydroxide and has a SiO2/Al2O3 molar ratio of 150 or more has been disclosed (Non-Patent Literature 2). The pentasil-type zeolite has a form having a repetitive structure in which a thin-layered pentasil-type zeolite having a thickness of about 2 nm extends linearly.